Universal metal melting furnace



Jan. 3o, 1940. W, A HUBR 2,188,539

UNIVERSAL METAL MELTING FURNACE 'HTTORNEK 0 ferrous metals. These metals, brass, aluminum Patented Jan. 30, 1940 UNITED STATES PATENT oFFlcE mesne assignments, to ReconstructionFinance Corporation, St.-Louis, Mo., a corporation `of the United States Application June 7, 1939, Serial No'.'277,751

y 5 Claims.

The object of my invention is to devise a universal metal melting furnace for practical use in colleges, manual training schools, laboratories and foundries. This furnace can be operated as a cupola for iron etc. by melting metal in direct contact with the fuel (coke) or the metal may be melted in iron pots or crucibles placed in the furnace which latter are surrounded'with fuel, when melting brass and aluminum or other nonetc. can also be melted in direct contact withthe fuel as is cast iron for many purposes.

The structure lends itself particularly well when used in small furnaces. The advantages over eX- isting small furnaces lie in the fact that the entire furnace opens, which permits it to be prepared for use in a very short time with a minimum of labor, and also permits effective cleaning at the end of a melt. In addition to this fact the furnace is very effective in melting brass and aluminum, the melting being carried on in a plurality of pots or crucibles at the same time, with very even heat, which is not possible with the ordinary open brass and aluminum furnace and can not be accomplished to anyextent in the ordinary small cupola.

'I'he furnace embodies the advantages of the ordinary enclosed melting furnace as well as the advantages of an open furnace. A further object is to supply an ordinary grate when ferrous metals are being melted and a solid plate when iron is being melted. The structure provides means for observing the melting process at all times andcan be accomplished with either a natural or forced draft. Means are provided for `easily opening and closing the doors and for sealing them in their closed positions.

With these and other objects in view my inven tion has relation to certain novel features of construction and arrangement of parts as will be hereinafter more fully described pointed out in the claims and illustrated in the drawings.

Fig. l is a top plan view.

Fig. 2 is a front elevation of the furnace showing the doors in their opened position.

Fig. 3 is a front elevation, the same as Fig. 2 showing the doors in their closed position.

, Fig. 4 is a vertical sectional elevation taken on the line 4--4 of Fig. 1.

Fig. 5 is a plan View of the plate used when iron is melted.

Fig. 6 is an enlarged fragmental cross vsection of the jointure between the doors and frame of A55 the furnace, showing the door in its closed posiflange I8 forms the ash box of the furnace.

(Cl. 2GB- 24) l tion with fire clay between the door and the frame "I of the furnace.

`Numeral 'I indicates a cylindrical shell posi tioned vertically on the support 8. The cylindrical shell 1 is formed of an upper portion 9 and intermediate portion lIl and the lower portion II. The three portions are secured together in an alignment in any conventional manner such as welding or riveting. The inner walls .of the three portions of the cylindrical shell 'I are lined The upper portion 9 of the `cylindrical shell 'I -has an internal and annular .flange I3 secured over the top row lof fire brick with re brick I2.

Numeral Ill designates a grate thatAA circumferential edge of the grate I4. Numeral I8 designates an annular flange formed within the cylindrical-'shell 'I near the support 8. The space -between the support 8 and the annular grate I4 is 4positioned in sliding engagement on the annular flange I8 so that the fiat surface I5, when the grate I4 is positioned on the annular flange i8 will be adjacent to the lateral walls of the cylindricaly shell 1. A hole is positioned in the wall ofthe lower portion I I ofthe cylindrical shell 'I so that when the grate I4 is slid into position the projection I6 will pass through this hole and extend beyond the outer vertical wall of the lower portion II of the cylindrical shell l.

Numeral I9 designates an annular lia-nge similar to annular flange I8, but in spaced relationship therewith so as to permit the sliding of the The grate I4 between the annular flanges I 8 and I9.v

Numerals 2 5 the upper shell door 2l may be locked in a closed 1 position. The shell door fasteners 25 are made o-f one portion 26 secured to the upper portions of the cylindrical shell 'I and another portion 2l secured to the upper shell door 2I. The portion 26 is an arm with a projection at its end. The portion 2'I is channelled at its free end, permitting the selective positioning of the portion 26 therein. The shell door fasteners are considered to be conventional structure. The similar shell door fasteners 28 are secured to the free end of the lower shell door 23 and hinges 24. Numeral 29 designates an ash door of conventional size and disposed in the lower portion of the lower shell door 23. By means of the ash door 29, access may be had to the ash box when the lower shell door 23 is closed. In order to seal the upper shell door 2l and the lower shell door 23 when closed the following construction is used which is specifically shown in Figure 6. Spaced from the free edge of the upper shell of door 2| and the lower shell door 23 is a projecting rib 30; this rib or male portion is so shaped as to engage the female portion 3l which is positioned internally near the free open edge of the upper shell portions 9 a-nd the lower shell portions I I. When the upper shell door 2l and the lower shell door 23 are closed, in order to secure a perfect seal, fire clay 32 is positioned in the female portion 3| so as to engage the male portion on the door. Numeral 33 designates an eye formed on the upper shell door 2| and 34 designates an eye formed on the lower shell door 23. The purposes of the eyes 33 and 34 are to permit insertion of hooks in order to open and close the shell doors. It is to be understood that as shown in Fig. 4 the upper shell door 2| as well as the lower shell door 23 are lined with fire brick I2 just as the stationary portion of cylindrical shell I is lined with fire brick. Numeral 35 designates a flight of stairs having the balustrades 36. The flight of stairs 35 permits access to the loading platform 3l'.

In order to effectively and simply open and close the shell doors 2| and 23, the following structure is employed. Numeral 38 designates a channel secured near the bottom of the upper shell door 2|; a roller 39 is mounted in rotative engagement on a shaft 4I), which is' journaled in the outer edges of the channel 38. Numeral 4I designates a shell door track which is secured at one end to the intermediate portion lli of the cylindrical shell 'I. This intermediate portion It is obviously stationary. The opposite end of the shell door track il is supported on the shell door track support 42. The shell door track has a channel section and is curvilinear. The roller 39 is positioned in rolling engagement on the upper face of the upper portion of the channel. Numeral 43 designates an arm secured to the lower shell portion II near its top and in substantial vertical alignment with the channel 38. Numeral 44 designates a roller mounted on a shaft 45 which in turn is secured to the outer end of the arm 43 so that the roller 44 is in engagement with the lower portion of the channel forming the shell door track 4|. By means of the rollers 39 and 44 and the shell door track 4| the movement of the upper shell door 2| and lower shell door 23 is facilitated and made positive. Such structure is necessary in order to move the heavy shell doors 2I and 23 and to permit accurate opening and closing in order to make and break the seal, the structure of which has been previously described. Numerals 46 designate air tuyres' having caps 4l. The air tuyres 45 are positioned diametrically opposite each other in the lower shell portion Il. Numeral 43 designates a spout formed in the lower shell door 23. Numeral 43 designates a blo-wer in fluid communication with the lower shell portion II. Numeral 50 designates a motor. The blower 49 and the motor 50 are operatively connected with the shaft 5I, so that the motor will actuate the blower in a conventional manner. Numeral 52 designates a blower intake and numeral 53 a cap for the blower intake. When cap 53 is removed the air is permitted to enter and is blown into the furnace above the grate I4 through conduits 56. Numeral 54 designates a hood which is suspended above the top of the cylindrical shell I in spaced relationship therewith for the purpose of conducting the production of combustion and heat from the top of the furnace when in operation out through the ceiling of the building in which the furnace is positioned by means of the pipe 55.

The operation of my furnace is as follows: Assuming the furnace is set up for operation in accordance with the description hereinbefore stated, when used as a cupola for melting cast iron, the upper shell door 2| is opened by inserting an iron bar into the eye 33 and rolling the roller 33 on the shell door track 4I. Lower shell door 23 is likewise opened its entire distance.

Insert solid bottom 20 into position on the annular flange I8, fill the female portion 3| with re clay 32. Close lower shell door 23 and secure it with the shell door fasteners 28. A sand bottom is placed on the solid bottom 2l) and the spout 48 is built up with clay. These operations are familiar to all cupola operators. The fire is then laid. Close the upper shell door 2| in the same manner that the lower shell door 23 was closed. The charging of fuel and metal is accomplished from the charging platform 3'I through the top of the furnace. The conventional fuel that is used is coke. The furnace is charged with alternate layers of coke and the metal that is to be melted. The molten metal fOWS from the spout 4a. At the end of the melt,

instead of dropping the bottom as in ordinary cupolas, open the upper shell door 2| and the lower shell door 23 to the outward limit of their open position and pull out the remains of the the upper shell door 2l omitting the re clay 32 until a hot bed of fire is up to within six or eight inches of the bottom` of the upper shell door 2|. Upper shell door 2| is now opened, all the way and iron pots or crucibles placed in the furnace and packed with small fuel to a level with the bottom of the upper shell door 2|, The melting is carried on very rapidly and evenly with the upper shell door 2| closed with a natural draft. A forced draft by use of a blower may be used if desired. The upper shell door 2| may be opened and closed from time to time for the addition of fuel or metal. The progress of the melting can be watched from the charging platform if desired. 'Ihe accumulation of ashes are removed from the ash pit as the melting proceeds. In order to easily remove the grate |4 or the solid bottom 20 after a melt, the projection I6 is struck with a s'ledge hammer thereby loosening and disengaging either the grate or solid bottom from the side walls of the cylindrical shell 'I and The lower shell f from the material that may adhere to it. By the insertion of a hook in the hole i1 the solid bottom or grate may be pulled out from the annular flange I8.

It will be seen that by the structure and operation described that the purposes of the invention stated herein are accomplished.

What I claim and mean to secure by Letters Patent is:

l. A furnace comprising a stationary shell made with three portions in vertical alignment permanently secured together, the upper and lower portions having lateral sections cutaway, doors secured to the upper and lower shell portions so as to selectively permit the closure of the cut away sections of said shell, a single track secured to the middle stationary shell portion, a U-shaped channel secured to the lower portion of said upper door, a roller secured to said channel, an arm secured to the lower portion of said lower door, a roller secured to said arm, both of said rollers being in engagement with said track, projecting ribs formed on said doors, grooves formed on the upper and lower portion of said shell, said projecting ribs and grooves so formed, dimensioned and positioned that said projecting ribs will extend into said grooves when said doors are in their closed positions, lire clay for selectively positioning between said projecting ribs and said grooves for sealing said doors to said shell when said doors are in their closed positions.

2. A furnace comprising a stationary shell made with three portions in vertical alignment permanently secured together, the upper and lower portions having lateral sections cut away. doors secured to the upper and lower shell portions so as to selectively permit the closure of the cut away sections of said shell, a single track secured to the middle stationary shell portions, a U-shaped channel secured to the lower portion of said upper door, a roller secured to said channel, an arm secured to the lower portion of said lower door, a roller secured to said arm, both of said rollers being in engagement with said track, projecting ribs formed on said doors, grooves formed on the upper and lower portion of said shell, said projecting ribs and grooves so formed, dimensioned and positioned that said projecting ribs will extend into said grooves when said doors are in their closed positions, re clay for selectively positioning between said projecting ribs and said grooves for sealing said doors to said shell when said doors are in their closed positions, shell door fasteners secured to said doors and the adjoining portions of said shell for selectively securing said doors in their closed positions, a spout positioned in said lower door, said shell and doors lined with a refractory material, an ash door secured in the lower door of said furnace.

3. A furnace comprising a stationary shell made with three portions secured in vertical alignment permanently together, the upper and lower portions having lateral sections cut away, doors secured to the upper and lower shell portions so as to selectively permit the closure of the cut away sections of said shell, a single track secured to the middle shell portion, a U-shaped channel secured to the lower portion of said upper door, a roller secured to said arm, both of said rollers being in engagement with said track, projecting ribs formed on said doors, grooves formed on the upper and lower portions of said shell, said projecting ribs and grooves so formed dimensioned and positioned that said projecting ribs will extend into said grooves whensaid doors are in their closed positions, re clay for selectively positioning between said projecting ribs and said grooves for sealing said doors to said shell when said doors are in their closed positions, shell door fasteners secured to said doors and the adjoining portions of said shell for selectively securing said doors in their closed positions, a spout positioned in said lower door, said shell and doors lined with a refractory material, an ash door secured in the lower door of said furnace, a solid bottom slidably secured in said lower shell portion, a projection formed on said solid bottom, said lower shell portion having a hole formed therein, of such size and so positioned that when said solid bottom is in position, said projection will extend through and beyond the hole formed in said lower shell portion.

4. -In a furnace, a solid substantially circular bottom for supporting the furnace fuel and charge, said solid Ibottom having opposite flat lateral surfaces, a projection for sliding engagement in and through a hole formed in the lower portionof the shell of said furnace, said solid bottom having a hole formed therein diametrical- 1y opposite said projection, said projection being parallel to the opposite flat lateral surfaces of vsaid solid bottom.

5. A furnace comprising a stationary shell made with three portions in vertical alignment permanently secured together, the upper and lower portions having lateral sections cut away, doors secured to the upper and lower shell portions so as to selectively permit the closure of the cut away sections of said shell, a curvlinear track secured at one end to the intermediate stationary portion of said shell, a support for a track for said doors, the free end of said curvlinear track supported on said support for a track for said doors, said track having a channel section, rollers secured to said doors, so that the roller secured to the upper door will be in rolling engagement on the upper flange of the channel of said track and that the roller secured to the lower door will be in rolling engagementv with the upper surface of the lower flange of the channel of said track. 

